In recent years, various outdoor wireless service systems, including the following, have become increasingly available: cellular phones, hot spot services for wireless LAN (Local Area Network), and WiMAX (Worldwide Interoperability for Microwave Access). In the broadcasting sector, digital terrestrial television broadcasting and the like have started. In order to make effective use of such various wireless services, the performance of antennas is important.
As communications technologies have advanced in recent years, small terminals, such as a cellular phone, PDA (Personal Digital Assistant) or laptop PC (Personal Computer), have been able to communicate at high speeds.
In a wireless communication process of such a terminal, radio waves are used. The terminal is usually equipped with an antenna. However, since the terminal is small in size, the terminal is, in many cases, equipped with a small antenna or small built-in antenna.
Meanwhile, it is known that as the antenna becomes physically larger, radiation efficiency and gain, which are important integrants in wireless communication, become better because of characteristics thereof.
The above-described small terminal device is generally equipped with only a small antenna. It is difficult to say that the performance of the antenna that the terminal device is equipped with is sufficiently high.
The problem is that it is not possible to obtain a sufficient receiving electric field needed for high-speed communication in a region where a radio wave propagation environment is not good, i.e. at a place where radio waves from a base station are weak. That is, the problem is that it is not possible to obtain sufficient S/N to perform high-speed communication.
To solve the problem, a relatively large external antenna is required. However, under the present circumstances, the problem is that it is difficult to store an existing external antenna in a bag or the like since the external antenna is three-dimensional and bulky.
If an antenna is stored in a goods storage tool such as a bag, it is necessary to take out the antenna from the bag and connect a coaxial cable to the antenna when the antenna is used.
Under such circumstances, the following are extremely useful: an antenna that can be easily stored in a goods storage tool such as a bag, and an electricity supply method that can be used without the antenna being taken out from the goods storage tool.